Light detection and ranging (LIDAR) is increasingly useful for providing range measurements in the vicinity of autonomous vehicles, robots and smart buildings. Traditionally, LIDAR systems have been placed on the exterior of host platforms (e.g. vehicles) with direct access to a FOV. While this is useful during research and development, external LIDAR placement with a single FOV poses challenges including aesthetics, long-term reliability and cost.
Flash LIDAR or time-of-flight (TOF) cameras are a class of scannerless LIDAR in which a laser or LED source illuminates a plurality of directions at once and a photodetector array such as a focal plane array (FPA) of avalanche photodiodes detects the timing of reflections from the plurality of directions. An ongoing challenge is that the photodetector array (e.g. single photon avalanche detector) can be the most expensive part of a flash LIDAR. Providing the LIDAR with an unobstructed view of the vicinity typically requires mounting the LIDAR on the exterior of the host platform, where it is subject to weather and damage. In a related aspect, external placement often only provides an unobstructed view of a portion of the surroundings. U.S. Patent Application 20150192677 to Yu addresses this challenge by disclosing multiple LIDAR sensor around a vehicle to provide adequate coverage, but does not address the associated cost and weight penalty.
U.S. Pat. No. 9,069,059 to Lionel discloses a LIDAR jammer that detects a laser emitter in the local environment by gathering light with an input lens into an input fiber optic cable coupled to a photodiode. While useful for laser detection somewhere in the surroundings, it does not address the challenge of constructing a detailed 3-D depth image. Therefore, the challenge of performing LIDAR measurements in a wide range of directions, while minimizing the number of LIDARs and protecting expensive LIDAR components remains.